Consideration of Initial Slippage

The joint type "Main member only" in RF‑/JOINTS Timber - Steel to Timber can also be applied for more than one connected member.

For a timber connection as shown in Figure 01, you can take into account the torsional spring rigidity (spring stiffness for rotation) of the connections. You can determine it by means of the slip modulus of the fastener and the polar moment of inertia of the connection.

In addition to determining loads, some particularities concerning the load combinatorics in timber design have to be considered. Contrary to steel structures, where the largest loading results from all unfavorable actions, in timber construction, the strength values depend on the load duration and timber humidity. Special characteristics have to be considered as well for the serviceability limit state design. The following article discusses the effects on the design of wooden elements and how this is possible with RSTAB and RFEM.

After the calculation, the RF‑/JOINTS Timber - Steel to Timber add‑on module lists joint stiffnesses of all individual members, among other things. The following design results are displayed:

• Check of minimum spacing
• Load-carrying capacity of single fastener
• Steel plates (bearing resistance and stress according to EC 3 and AISC)
• Stress analysis with reduced timber cross‑section
• Block shear failure
• Total load carrying-capacity (including stiffness determination, transversal tension design according to EC 5, and others)
• Fire resistance design according to EN 1995‑1‑2

At first, the governing joint designs are arranged in groups and displayed with the basic geometry of the joint in the first result window. In the other result windows, you can see all fundamental design details.

Dimensions, material properties, and welds important for the connection construction are displayed immediately and can be printed directly. Similarly, export to DXF-file is enabled. It is possible to visualize the connections in RF‑/JOINTS Timber - Steel to Timber or in the RFEM/RSTAB model.

All graphics can be included in the RFEM/RSTAB printout report or printed directly. Due to the scaled output, an optimal visual check is possible as early as in the design phase.

• Design of hinged, bending resistant, and semi-rigid connections
• Definition of up to 5 steel plates slotted in timber beams
• Up to 8 members connected to one node
• Thickness of steel plate 5 mm – 40 mm
• All sizes of fasteners
• Automatic check of the minimum distance between fasteners
• Optional free definition of fastener distances
• Definition of asymmetrical fastener arrangements (for example, any polygonal chains)
• Graphical visualization of joints in the add-on module and in RFEM/RSTAB
• All required steel and timber designs, including reduction of cross‑section values
• Design of transversal tension reinforcement (for EN 1995‑1‑1 only)
• Export of the member eccentricities to RFEM/RSTAB to be considered in the determination of internal forces
• Dowel length optionally shorter than cross-section width (for wooden plugs)
• DXF Export of Connection Geometry
• Fire resistance design according to EN 1995‑1‑2